Tedizolid is a compound having an oxazolidinone structure, and has the chemical name “(5R)-3-{3-fluoro-4-[6-(2-methyl-2H-tetrazol-5-yl)pyridin-3-yl]phenyl}-5-(hydroxymethyl)-1,3-oxazolidin-2-one”. This tedizolid is an oxazolidinone-based derivative compound (disclosed in Korean Patent Application Publication No. 10-2005-0061271) that is useful as a disinfecting agent, and is sold in the form of an oral formulation and an injectable formulation under the trade name of SIVEXTRO, with the permission of the U.S. Food and Drug Administration.
Korean Patent Application Publication No. 10-2005-0061271 discloses a method of preparing an intermediate for an oxazolidinone derivative, as shown in Scheme 1 below.

In the preparation procedures of Scheme 1, however, the methylation of tetrazole is not selective, undesirably producing tetrazole in which the methyl group is added to a different position.
This is because the NH bonding of tetrazole is present in two tautomer forms. Hence, when the methyl group is added to tetrazole, two kinds of compounds, namely 1,5-disubstituted tetrazole and 2,5-disubstituted tetrazole, are formed.
The methylation of tetrazole in this way is not suitable for industrial use because of the low yield and low selectivity to desired compounds, and also suffers from high production costs.
Furthermore, dimethyl sulfate, diazomethane, or trimethylsilyl diazomethane, useful for the methylation of tetrazole, is highly toxic, highly explosive, and expensive, and is thus inappropriate for industrial mass production.